/*!
 * vue-i18n v8.9.0 
 * (c) 2019 kazuya kawaguchi
 * Released under the MIT License.
 */
(function (global, factory) {
    typeof exports === 'object' && typeof module !== 'undefined' ? module.exports = factory() :
    typeof define === 'function' && define.amd ? define(factory) :
    (global.VueI18n = factory());
  }(this, (function () { 'use strict';
  
    /*  */
  
    /**
     * utilities
     */
  
    function warn (msg, err) {
      if (typeof console !== 'undefined') {
        console.warn('[vue-i18n] ' + msg);
        /* istanbul ignore if */
        if (err) {
          console.warn(err.stack);
        }
      }
    }
  
    function isObject (obj) {
      return obj !== null && typeof obj === 'object'
    }
  
    var toString = Object.prototype.toString;
    var OBJECT_STRING = '[object Object]';
    function isPlainObject (obj) {
      return toString.call(obj) === OBJECT_STRING
    }
  
    function isNull (val) {
      return val === null || val === undefined
    }
  
    function parseArgs () {
      var args = [], len = arguments.length;
      while ( len-- ) args[ len ] = arguments[ len ];
  
      var locale = null;
      var params = null;
      if (args.length === 1) {
        if (isObject(args[0]) || Array.isArray(args[0])) {
          params = args[0];
        } else if (typeof args[0] === 'string') {
          locale = args[0];
        }
      } else if (args.length === 2) {
        if (typeof args[0] === 'string') {
          locale = args[0];
        }
        /* istanbul ignore if */
        if (isObject(args[1]) || Array.isArray(args[1])) {
          params = args[1];
        }
      }
  
      return { locale: locale, params: params }
    }
  
    function looseClone (obj) {
      return JSON.parse(JSON.stringify(obj))
    }
  
    function remove (arr, item) {
      if (arr.length) {
        var index = arr.indexOf(item);
        if (index > -1) {
          return arr.splice(index, 1)
        }
      }
    }
  
    var hasOwnProperty = Object.prototype.hasOwnProperty;
    function hasOwn (obj, key) {
      return hasOwnProperty.call(obj, key)
    }
  
    function merge (target) {
      var arguments$1 = arguments;
  
      var output = Object(target);
      for (var i = 1; i < arguments.length; i++) {
        var source = arguments$1[i];
        if (source !== undefined && source !== null) {
          var key = (void 0);
          for (key in source) {
            if (hasOwn(source, key)) {
              if (isObject(source[key])) {
                output[key] = merge(output[key], source[key]);
              } else {
                output[key] = source[key];
              }
            }
          }
        }
      }
      return output
    }
  
    function looseEqual (a, b) {
      if (a === b) { return true }
      var isObjectA = isObject(a);
      var isObjectB = isObject(b);
      if (isObjectA && isObjectB) {
        try {
          var isArrayA = Array.isArray(a);
          var isArrayB = Array.isArray(b);
          if (isArrayA && isArrayB) {
            return a.length === b.length && a.every(function (e, i) {
              return looseEqual(e, b[i])
            })
          } else if (!isArrayA && !isArrayB) {
            var keysA = Object.keys(a);
            var keysB = Object.keys(b);
            return keysA.length === keysB.length && keysA.every(function (key) {
              return looseEqual(a[key], b[key])
            })
          } else {
            /* istanbul ignore next */
            return false
          }
        } catch (e) {
          /* istanbul ignore next */
          return false
        }
      } else if (!isObjectA && !isObjectB) {
        return String(a) === String(b)
      } else {
        return false
      }
    }
  
    /*  */
  
    function extend (Vue) {
      if (!Vue.prototype.hasOwnProperty('$i18n')) {
        // $FlowFixMe
        Object.defineProperty(Vue.prototype, '$i18n', {
          get: function get () { return this._i18n }
        });
      }
  
      Vue.prototype.$t = function (key) {
        var values = [], len = arguments.length - 1;
        while ( len-- > 0 ) values[ len ] = arguments[ len + 1 ];
  
        var i18n = this.$i18n;
        return i18n._t.apply(i18n, [ key, i18n.locale, i18n._getMessages(), this ].concat( values ))
      };
  
      Vue.prototype.$tc = function (key, choice) {
        var values = [], len = arguments.length - 2;
        while ( len-- > 0 ) values[ len ] = arguments[ len + 2 ];
  
        var i18n = this.$i18n;
        return i18n._tc.apply(i18n, [ key, i18n.locale, i18n._getMessages(), this, choice ].concat( values ))
      };
  
      Vue.prototype.$te = function (key, locale) {
        var i18n = this.$i18n;
        return i18n._te(key, i18n.locale, i18n._getMessages(), locale)
      };
  
      Vue.prototype.$d = function (value) {
        var ref;
  
        var args = [], len = arguments.length - 1;
        while ( len-- > 0 ) args[ len ] = arguments[ len + 1 ];
        return (ref = this.$i18n).d.apply(ref, [ value ].concat( args ))
      };
  
      Vue.prototype.$n = function (value) {
        var ref;
  
        var args = [], len = arguments.length - 1;
        while ( len-- > 0 ) args[ len ] = arguments[ len + 1 ];
        return (ref = this.$i18n).n.apply(ref, [ value ].concat( args ))
      };
    }
  
    /*  */
  
    var mixin = {
      beforeCreate: function beforeCreate () {
        var options = this.$options;
        options.i18n = options.i18n || (options.__i18n ? {} : null);
  
        if (options.i18n) {
          if (options.i18n instanceof VueI18n) {
            // init locale messages via custom blocks
            if (options.__i18n) {
              try {
                var localeMessages = {};
                options.__i18n.forEach(function (resource) {
                  localeMessages = merge(localeMessages, JSON.parse(resource));
                });
                Object.keys(localeMessages).forEach(function (locale) {
                  options.i18n.mergeLocaleMessage(locale, localeMessages[locale]);
                });
              } catch (e) {
                {
                  warn("Cannot parse locale messages via custom blocks.", e);
                }
              }
            }
            this._i18n = options.i18n;
            this._i18nWatcher = this._i18n.watchI18nData();
            this._i18n.subscribeDataChanging(this);
            this._subscribing = true;
          } else if (isPlainObject(options.i18n)) {
            // component local i18n
            if (this.$root && this.$root.$i18n && this.$root.$i18n instanceof VueI18n) {
              options.i18n.root = this.$root;
              options.i18n.formatter = this.$root.$i18n.formatter;
              options.i18n.fallbackLocale = this.$root.$i18n.fallbackLocale;
              options.i18n.silentTranslationWarn = this.$root.$i18n.silentTranslationWarn;
              options.i18n.silentFallbackWarn = this.$root.$i18n.silentFallbackWarn;
              options.i18n.pluralizationRules = this.$root.$i18n.pluralizationRules;
              options.i18n.preserveDirectiveContent = this.$root.$i18n.preserveDirectiveContent;
            }
  
            // init locale messages via custom blocks
            if (options.__i18n) {
              try {
                var localeMessages$1 = {};
                options.__i18n.forEach(function (resource) {
                  localeMessages$1 = merge(localeMessages$1, JSON.parse(resource));
                });
                options.i18n.messages = localeMessages$1;
              } catch (e) {
                {
                  warn("Cannot parse locale messages via custom blocks.", e);
                }
              }
            }
  
            this._i18n = new VueI18n(options.i18n);
            this._i18nWatcher = this._i18n.watchI18nData();
            this._i18n.subscribeDataChanging(this);
            this._subscribing = true;
  
            if (options.i18n.sync === undefined || !!options.i18n.sync) {
              this._localeWatcher = this.$i18n.watchLocale();
            }
          } else {
            {
              warn("Cannot be interpreted 'i18n' option.");
            }
          }
        } else if (this.$root && this.$root.$i18n && this.$root.$i18n instanceof VueI18n) {
          // root i18n
          this._i18n = this.$root.$i18n;
          this._i18n.subscribeDataChanging(this);
          this._subscribing = true;
        } else if (options.parent && options.parent.$i18n && options.parent.$i18n instanceof VueI18n) {
          // parent i18n
          this._i18n = options.parent.$i18n;
          this._i18n.subscribeDataChanging(this);
          this._subscribing = true;
        }
      },
  
      beforeDestroy: function beforeDestroy () {
        if (!this._i18n) { return }
  
        var self = this;
        this.$nextTick(function () {
          if (self._subscribing) {
            self._i18n.unsubscribeDataChanging(self);
            delete self._subscribing;
          }
  
          if (self._i18nWatcher) {
            self._i18nWatcher();
            self._i18n.destroyVM();
            delete self._i18nWatcher;
          }
  
          if (self._localeWatcher) {
            self._localeWatcher();
            delete self._localeWatcher;
          }
  
          self._i18n = null;
        });
      }
    };
  
    /*  */
  
    var component = {
      name: 'i18n',
      functional: true,
      props: {
        tag: {
          type: String,
          default: 'span'
        },
        path: {
          type: String,
          required: true
        },
        locale: {
          type: String
        },
        places: {
          type: [Array, Object]
        }
      },
      render: function render (h, ref) {
        var props = ref.props;
        var data = ref.data;
        var children = ref.children;
        var parent = ref.parent;
  
        var i18n = parent.$i18n;
  
        children = (children || []).filter(function (child) {
          return child.tag || (child.text = child.text.trim())
        });
  
        if (!i18n) {
          {
            warn('Cannot find VueI18n instance!');
          }
          return children
        }
  
        var path = props.path;
        var locale = props.locale;
  
        var params = {};
        var places = props.places || {};
  
        var hasPlaces = Array.isArray(places)
          ? places.length > 0
          : Object.keys(places).length > 0;
  
        var everyPlace = children.every(function (child) {
          if (child.data && child.data.attrs) {
            var place = child.data.attrs.place;
            return (typeof place !== 'undefined') && place !== ''
          }
        });
  
        if (hasPlaces && children.length > 0 && !everyPlace) {
          warn('If places prop is set, all child elements must have place prop set.');
        }
  
        if (Array.isArray(places)) {
          places.forEach(function (el, i) {
            params[i] = el;
          });
        } else {
          Object.keys(places).forEach(function (key) {
            params[key] = places[key];
          });
        }
  
        children.forEach(function (child, i) {
          var key = everyPlace
            ? ("" + (child.data.attrs.place))
            : ("" + i);
          params[key] = child;
        });
  
        return h(props.tag, data, i18n.i(path, locale, params))
      }
    };
  
    /*  */
  
    function bind (el, binding, vnode) {
      if (!assert(el, vnode)) { return }
  
      t(el, binding, vnode);
    }
  
    function update (el, binding, vnode, oldVNode) {
      if (!assert(el, vnode)) { return }
  
      var i18n = vnode.context.$i18n;
      if (localeEqual(el, vnode) &&
        (looseEqual(binding.value, binding.oldValue) &&
         looseEqual(el._localeMessage, i18n.getLocaleMessage(i18n.locale)))) { return }
  
      t(el, binding, vnode);
    }
  
    function unbind (el, binding, vnode, oldVNode) {
      var vm = vnode.context;
      if (!vm) {
        warn('Vue instance does not exists in VNode context');
        return
      }
  
      var i18n = vnode.context.$i18n || {};
      if (!binding.modifiers.preserve && !i18n.preserveDirectiveContent) {
        el.textContent = '';
      }
      el._vt = undefined;
      delete el['_vt'];
      el._locale = undefined;
      delete el['_locale'];
      el._localeMessage = undefined;
      delete el['_localeMessage'];
    }
  
    function assert (el, vnode) {
      var vm = vnode.context;
      if (!vm) {
        warn('Vue instance does not exists in VNode context');
        return false
      }
  
      if (!vm.$i18n) {
        warn('VueI18n instance does not exists in Vue instance');
        return false
      }
  
      return true
    }
  
    function localeEqual (el, vnode) {
      var vm = vnode.context;
      return el._locale === vm.$i18n.locale
    }
  
    function t (el, binding, vnode) {
      var ref$1, ref$2;
  
      var value = binding.value;
  
      var ref = parseValue(value);
      var path = ref.path;
      var locale = ref.locale;
      var args = ref.args;
      var choice = ref.choice;
      if (!path && !locale && !args) {
        warn('value type not supported');
        return
      }
  
      if (!path) {
        warn('`path` is required in v-t directive');
        return
      }
  
      var vm = vnode.context;
      if (choice) {
        el._vt = el.textContent = (ref$1 = vm.$i18n).tc.apply(ref$1, [ path, choice ].concat( makeParams(locale, args) ));
      } else {
        el._vt = el.textContent = (ref$2 = vm.$i18n).t.apply(ref$2, [ path ].concat( makeParams(locale, args) ));
      }
      el._locale = vm.$i18n.locale;
      el._localeMessage = vm.$i18n.getLocaleMessage(vm.$i18n.locale);
    }
  
    function parseValue (value) {
      var path;
      var locale;
      var args;
      var choice;
  
      if (typeof value === 'string') {
        path = value;
      } else if (isPlainObject(value)) {
        path = value.path;
        locale = value.locale;
        args = value.args;
        choice = value.choice;
      }
  
      return { path: path, locale: locale, args: args, choice: choice }
    }
  
    function makeParams (locale, args) {
      var params = [];
  
      locale && params.push(locale);
      if (args && (Array.isArray(args) || isPlainObject(args))) {
        params.push(args);
      }
  
      return params
    }
  
    var Vue;
  
    function install (_Vue) {
      /* istanbul ignore if */
      if (install.installed && _Vue === Vue) {
        warn('already installed.');
        return
      }
      install.installed = true;
  
      Vue = _Vue;
  
      var version = (Vue.version && Number(Vue.version.split('.')[0])) || -1;
      /* istanbul ignore if */
      if (version < 2) {
        warn(("vue-i18n (" + (install.version) + ") need to use Vue 2.0 or later (Vue: " + (Vue.version) + ")."));
        return
      }
  
      extend(Vue);
      Vue.mixin(mixin);
      Vue.directive('t', { bind: bind, update: update, unbind: unbind });
      Vue.component(component.name, component);
  
      // use simple mergeStrategies to prevent i18n instance lose '__proto__'
      var strats = Vue.config.optionMergeStrategies;
      strats.i18n = function (parentVal, childVal) {
        return childVal === undefined
          ? parentVal
          : childVal
      };
    }
  
    /*  */
  
    var BaseFormatter = function BaseFormatter () {
      this._caches = Object.create(null);
    };
  
    BaseFormatter.prototype.interpolate = function interpolate (message, values) {
      if (!values) {
        return [message]
      }
      var tokens = this._caches[message];
      if (!tokens) {
        tokens = parse(message);
        this._caches[message] = tokens;
      }
      return compile(tokens, values)
    };
  
  
  
    var RE_TOKEN_LIST_VALUE = /^(?:\d)+/;
    var RE_TOKEN_NAMED_VALUE = /^(?:\w)+/;
  
    function parse (format) {
      var tokens = [];
      var position = 0;
  
      var text = '';
      while (position < format.length) {
        var char = format[position++];
        if (char === '{') {
          if (text) {
            tokens.push({ type: 'text', value: text });
          }
  
          text = '';
          var sub = '';
          char = format[position++];
          while (char !== undefined && char !== '}') {
            sub += char;
            char = format[position++];
          }
          var isClosed = char === '}';
  
          var type = RE_TOKEN_LIST_VALUE.test(sub)
            ? 'list'
            : isClosed && RE_TOKEN_NAMED_VALUE.test(sub)
              ? 'named'
              : 'unknown';
          tokens.push({ value: sub, type: type });
        } else if (char === '%') {
          // when found rails i18n syntax, skip text capture
          if (format[(position)] !== '{') {
            text += char;
          }
        } else {
          text += char;
        }
      }
  
      text && tokens.push({ type: 'text', value: text });
  
      return tokens
    }
  
    function compile (tokens, values) {
      var compiled = [];
      var index = 0;
  
      var mode = Array.isArray(values)
        ? 'list'
        : isObject(values)
          ? 'named'
          : 'unknown';
      if (mode === 'unknown') { return compiled }
  
      while (index < tokens.length) {
        var token = tokens[index];
        switch (token.type) {
          case 'text':
            compiled.push(token.value);
            break
          case 'list':
            compiled.push(values[parseInt(token.value, 10)]);
            break
          case 'named':
            if (mode === 'named') {
              compiled.push((values)[token.value]);
            } else {
              {
                warn(("Type of token '" + (token.type) + "' and format of value '" + mode + "' don't match!"));
              }
            }
            break
          case 'unknown':
            {
              warn("Detect 'unknown' type of token!");
            }
            break
        }
        index++;
      }
  
      return compiled
    }
  
    /*  */
  
    /**
     *  Path parser
     *  - Inspired:
     *    Vue.js Path parser
     */
  
    // actions
    var APPEND = 0;
    var PUSH = 1;
    var INC_SUB_PATH_DEPTH = 2;
    var PUSH_SUB_PATH = 3;
  
    // states
    var BEFORE_PATH = 0;
    var IN_PATH = 1;
    var BEFORE_IDENT = 2;
    var IN_IDENT = 3;
    var IN_SUB_PATH = 4;
    var IN_SINGLE_QUOTE = 5;
    var IN_DOUBLE_QUOTE = 6;
    var AFTER_PATH = 7;
    var ERROR = 8;
  
    var pathStateMachine = [];
  
    pathStateMachine[BEFORE_PATH] = {
      'ws': [BEFORE_PATH],
      'ident': [IN_IDENT, APPEND],
      '[': [IN_SUB_PATH],
      'eof': [AFTER_PATH]
    };
  
    pathStateMachine[IN_PATH] = {
      'ws': [IN_PATH],
      '.': [BEFORE_IDENT],
      '[': [IN_SUB_PATH],
      'eof': [AFTER_PATH]
    };
  
    pathStateMachine[BEFORE_IDENT] = {
      'ws': [BEFORE_IDENT],
      'ident': [IN_IDENT, APPEND],
      '0': [IN_IDENT, APPEND],
      'number': [IN_IDENT, APPEND]
    };
  
    pathStateMachine[IN_IDENT] = {
      'ident': [IN_IDENT, APPEND],
      '0': [IN_IDENT, APPEND],
      'number': [IN_IDENT, APPEND],
      'ws': [IN_PATH, PUSH],
      '.': [BEFORE_IDENT, PUSH],
      '[': [IN_SUB_PATH, PUSH],
      'eof': [AFTER_PATH, PUSH]
    };
  
    pathStateMachine[IN_SUB_PATH] = {
      "'": [IN_SINGLE_QUOTE, APPEND],
      '"': [IN_DOUBLE_QUOTE, APPEND],
      '[': [IN_SUB_PATH, INC_SUB_PATH_DEPTH],
      ']': [IN_PATH, PUSH_SUB_PATH],
      'eof': ERROR,
      'else': [IN_SUB_PATH, APPEND]
    };
  
    pathStateMachine[IN_SINGLE_QUOTE] = {
      "'": [IN_SUB_PATH, APPEND],
      'eof': ERROR,
      'else': [IN_SINGLE_QUOTE, APPEND]
    };
  
    pathStateMachine[IN_DOUBLE_QUOTE] = {
      '"': [IN_SUB_PATH, APPEND],
      'eof': ERROR,
      'else': [IN_DOUBLE_QUOTE, APPEND]
    };
  
    /**
     * Check if an expression is a literal value.
     */
  
    var literalValueRE = /^\s?(?:true|false|-?[\d.]+|'[^']*'|"[^"]*")\s?$/;
    function isLiteral (exp) {
      return literalValueRE.test(exp)
    }
  
    /**
     * Strip quotes from a string
     */
  
    function stripQuotes (str) {
      var a = str.charCodeAt(0);
      var b = str.charCodeAt(str.length - 1);
      return a === b && (a === 0x22 || a === 0x27)
        ? str.slice(1, -1)
        : str
    }
  
    /**
     * Determine the type of a character in a keypath.
     */
  
    function getPathCharType (ch) {
      if (ch === undefined || ch === null) { return 'eof' }
  
      var code = ch.charCodeAt(0);
  
      switch (code) {
        case 0x5B: // [
        case 0x5D: // ]
        case 0x2E: // .
        case 0x22: // "
        case 0x27: // '
          return ch
  
        case 0x5F: // _
        case 0x24: // $
        case 0x2D: // -
          return 'ident'
  
        case 0x20: // Space
        case 0x09: // Tab
        case 0x0A: // Newline
        case 0x0D: // Return
        case 0xA0:  // No-break space
        case 0xFEFF:  // Byte Order Mark
        case 0x2028:  // Line Separator
        case 0x2029:  // Paragraph Separator
          return 'ws'
      }
  
      return 'ident'
    }
  
    /**
     * Format a subPath, return its plain form if it is
     * a literal string or number. Otherwise prepend the
     * dynamic indicator (*).
     */
  
    function formatSubPath (path) {
      var trimmed = path.trim();
      // invalid leading 0
      if (path.charAt(0) === '0' && isNaN(path)) { return false }
  
      return isLiteral(trimmed) ? stripQuotes(trimmed) : '*' + trimmed
    }
  
    /**
     * Parse a string path into an array of segments
     */
  
    function parse$1 (path) {
      var keys = [];
      var index = -1;
      var mode = BEFORE_PATH;
      var subPathDepth = 0;
      var c;
      var key;
      var newChar;
      var type;
      var transition;
      var action;
      var typeMap;
      var actions = [];
  
      actions[PUSH] = function () {
        if (key !== undefined) {
          keys.push(key);
          key = undefined;
        }
      };
  
      actions[APPEND] = function () {
        if (key === undefined) {
          key = newChar;
        } else {
          key += newChar;
        }
      };
  
      actions[INC_SUB_PATH_DEPTH] = function () {
        actions[APPEND]();
        subPathDepth++;
      };
  
      actions[PUSH_SUB_PATH] = function () {
        if (subPathDepth > 0) {
          subPathDepth--;
          mode = IN_SUB_PATH;
          actions[APPEND]();
        } else {
          subPathDepth = 0;
          key = formatSubPath(key);
          if (key === false) {
            return false
          } else {
            actions[PUSH]();
          }
        }
      };
  
      function maybeUnescapeQuote () {
        var nextChar = path[index + 1];
        if ((mode === IN_SINGLE_QUOTE && nextChar === "'") ||
          (mode === IN_DOUBLE_QUOTE && nextChar === '"')) {
          index++;
          newChar = '\\' + nextChar;
          actions[APPEND]();
          return true
        }
      }
  
      while (mode !== null) {
        index++;
        c = path[index];
  
        if (c === '\\' && maybeUnescapeQuote()) {
          continue
        }
  
        type = getPathCharType(c);
        typeMap = pathStateMachine[mode];
        transition = typeMap[type] || typeMap['else'] || ERROR;
  
        if (transition === ERROR) {
          return // parse error
        }
  
        mode = transition[0];
        action = actions[transition[1]];
        if (action) {
          newChar = transition[2];
          newChar = newChar === undefined
            ? c
            : newChar;
          if (action() === false) {
            return
          }
        }
  
        if (mode === AFTER_PATH) {
          return keys
        }
      }
    }
  
  
  
  
  
    var I18nPath = function I18nPath () {
      this._cache = Object.create(null);
    };
  
    /**
     * External parse that check for a cache hit first
     */
    I18nPath.prototype.parsePath = function parsePath (path) {
      var hit = this._cache[path];
      if (!hit) {
        hit = parse$1(path);
        if (hit) {
          this._cache[path] = hit;
        }
      }
      return hit || []
    };
  
    /**
     * Get path value from path string
     */
    I18nPath.prototype.getPathValue = function getPathValue (obj, path) {
      if (!isObject(obj)) { return null }
  
      var paths = this.parsePath(path);
      if (paths.length === 0) {
        return null
      } else {
        var length = paths.length;
        var last = obj;
        var i = 0;
        while (i < length) {
          var value = last[paths[i]];
          if (value === undefined) {
            return null
          }
          last = value;
          i++;
        }
  
        return last
      }
    };
  
    /*  */
  
  
  
    var numberFormatKeys = [
      'style',
      'currency',
      'currencyDisplay',
      'useGrouping',
      'minimumIntegerDigits',
      'minimumFractionDigits',
      'maximumFractionDigits',
      'minimumSignificantDigits',
      'maximumSignificantDigits',
      'localeMatcher',
      'formatMatcher'
    ];
    var linkKeyMatcher = /(?:@(?:\.[a-z]+)?:(?:[\w\-_|.]+|\([\w\-_|.]+\)))/g;
    var linkKeyPrefixMatcher = /^@(?:\.([a-z]+))?:/;
    var bracketsMatcher = /[()]/g;
    var formatters = {
      'upper': function (str) { return str.toLocaleUpperCase(); },
      'lower': function (str) { return str.toLocaleLowerCase(); }
    };
  
    var defaultFormatter = new BaseFormatter();
  
    var VueI18n = function VueI18n (options) {
      var this$1 = this;
      if ( options === void 0 ) options = {};
  
      // Auto install if it is not done yet and `window` has `Vue`.
      // To allow users to avoid auto-installation in some cases,
      // this code should be placed here. See #290
      /* istanbul ignore if */
      if (!Vue && typeof window !== 'undefined' && window.Vue) {
        install(window.Vue);
      }
  
      var locale = options.locale || 'en-US';
      var fallbackLocale = options.fallbackLocale || 'en-US';
      var messages = options.messages || {};
      var dateTimeFormats = options.dateTimeFormats || {};
      var numberFormats = options.numberFormats || {};
  
      this._vm = null;
      this._formatter = options.formatter || defaultFormatter;
      this._missing = options.missing || null;
      this._root = options.root || null;
      this._sync = options.sync === undefined ? true : !!options.sync;
      this._fallbackRoot = options.fallbackRoot === undefined
        ? true
        : !!options.fallbackRoot;
      this._silentTranslationWarn = options.silentTranslationWarn === undefined
        ? false
        : !!options.silentTranslationWarn;
      this._silentFallbackWarn = options.silentFallbackWarn === undefined
        ? false
        : !!options.silentFallbackWarn;
      this._dateTimeFormatters = {};
      this._numberFormatters = {};
      this._path = new I18nPath();
      this._dataListeners = [];
      this._preserveDirectiveContent = options.preserveDirectiveContent === undefined
        ? false
        : !!options.preserveDirectiveContent;
      this.pluralizationRules = options.pluralizationRules || {};
  
      this._exist = function (message, key) {
        if (!message || !key) { return false }
        if (!isNull(this$1._path.getPathValue(message, key))) { return true }
        // fallback for flat key
        if (message[key]) { return true }
        return false
      };
  
      this._initVM({
        locale: locale,
        fallbackLocale: fallbackLocale,
        messages: messages,
        dateTimeFormats: dateTimeFormats,
        numberFormats: numberFormats
      });
    };
  
    var prototypeAccessors = { vm: { configurable: true },messages: { configurable: true },dateTimeFormats: { configurable: true },numberFormats: { configurable: true },availableLocales: { configurable: true },locale: { configurable: true },fallbackLocale: { configurable: true },missing: { configurable: true },formatter: { configurable: true },silentTranslationWarn: { configurable: true },silentFallbackWarn: { configurable: true },preserveDirectiveContent: { configurable: true } };
  
    VueI18n.prototype._initVM = function _initVM (data) {
      var silent = Vue.config.silent;
      Vue.config.silent = true;
      this._vm = new Vue({ data: data });
      Vue.config.silent = silent;
    };
  
    VueI18n.prototype.destroyVM = function destroyVM () {
      this._vm.$destroy();
    };
  
    VueI18n.prototype.subscribeDataChanging = function subscribeDataChanging (vm) {
      this._dataListeners.push(vm);
    };
  
    VueI18n.prototype.unsubscribeDataChanging = function unsubscribeDataChanging (vm) {
      remove(this._dataListeners, vm);
    };
  
    VueI18n.prototype.watchI18nData = function watchI18nData () {
      var self = this;
      return this._vm.$watch('$data', function () {
        var i = self._dataListeners.length;
        while (i--) {
          Vue.nextTick(function () {
            self._dataListeners[i] && self._dataListeners[i].$forceUpdate();
          });
        }
      }, { deep: true })
    };
  
    VueI18n.prototype.watchLocale = function watchLocale () {
      /* istanbul ignore if */
      if (!this._sync || !this._root) { return null }
      var target = this._vm;
      return this._root.$i18n.vm.$watch('locale', function (val) {
        target.$set(target, 'locale', val);
        target.$forceUpdate();
      }, { immediate: true })
    };
  
    prototypeAccessors.vm.get = function () { return this._vm };
  
    prototypeAccessors.messages.get = function () { return looseClone(this._getMessages()) };
    prototypeAccessors.dateTimeFormats.get = function () { return looseClone(this._getDateTimeFormats()) };
    prototypeAccessors.numberFormats.get = function () { return looseClone(this._getNumberFormats()) };
    prototypeAccessors.availableLocales.get = function () { return Object.keys(this.messages).sort() };
  
    prototypeAccessors.locale.get = function () { return this._vm.locale };
    prototypeAccessors.locale.set = function (locale) {
      this._vm.$set(this._vm, 'locale', locale);
    };
  
    prototypeAccessors.fallbackLocale.get = function () { return this._vm.fallbackLocale };
    prototypeAccessors.fallbackLocale.set = function (locale) {
      this._vm.$set(this._vm, 'fallbackLocale', locale);
    };
  
    prototypeAccessors.missing.get = function () { return this._missing };
    prototypeAccessors.missing.set = function (handler) { this._missing = handler; };
  
    prototypeAccessors.formatter.get = function () { return this._formatter };
    prototypeAccessors.formatter.set = function (formatter) { this._formatter = formatter; };
  
    prototypeAccessors.silentTranslationWarn.get = function () { return this._silentTranslationWarn };
    prototypeAccessors.silentTranslationWarn.set = function (silent) { this._silentTranslationWarn = silent; };
  
    prototypeAccessors.silentFallbackWarn.get = function () { return this._silentFallbackWarn };
    prototypeAccessors.silentFallbackWarn.set = function (silent) { this._silentFallbackWarn = silent; };
  
    prototypeAccessors.preserveDirectiveContent.get = function () { return this._preserveDirectiveContent };
    prototypeAccessors.preserveDirectiveContent.set = function (preserve) { this._preserveDirectiveContent = preserve; };
  
    VueI18n.prototype._getMessages = function _getMessages () { return this._vm.messages };
    VueI18n.prototype._getDateTimeFormats = function _getDateTimeFormats () { return this._vm.dateTimeFormats };
    VueI18n.prototype._getNumberFormats = function _getNumberFormats () { return this._vm.numberFormats };
  
    VueI18n.prototype._warnDefault = function _warnDefault (locale, key, result, vm, values) {
      if (!isNull(result)) { return result }
      if (this._missing) {
        var missingRet = this._missing.apply(null, [locale, key, vm, values]);
        if (typeof missingRet === 'string') {
          return missingRet
        }
      } else {
        if (!this._silentTranslationWarn) {
          warn(
            "Cannot translate the value of keypath '" + key + "'. " +
            'Use the value of keypath as default.'
          );
        }
      }
      return key
    };
  
    VueI18n.prototype._isFallbackRoot = function _isFallbackRoot (val) {
      return !val && !isNull(this._root) && this._fallbackRoot
    };
  
    VueI18n.prototype._isSilentFallback = function _isSilentFallback (locale) {
      return this._silentFallbackWarn && (this._isFallbackRoot() || locale !== this.fallbackLocale)
    };
  
    VueI18n.prototype._interpolate = function _interpolate (
      locale,
      message,
      key,
      host,
      interpolateMode,
      values,
      visitedLinkStack
    ) {
      if (!message) { return null }
  
      var pathRet = this._path.getPathValue(message, key);
      if (Array.isArray(pathRet) || isPlainObject(pathRet)) { return pathRet }
  
      var ret;
      if (isNull(pathRet)) {
        /* istanbul ignore else */
        if (isPlainObject(message)) {
          ret = message[key];
          if (typeof ret !== 'string') {
            if (!this._silentTranslationWarn && !this._isSilentFallback(locale)) {
              warn(("Value of key '" + key + "' is not a string!"));
            }
            return null
          }
        } else {
          return null
        }
      } else {
        /* istanbul ignore else */
        if (typeof pathRet === 'string') {
          ret = pathRet;
        } else {
          if (!this._silentTranslationWarn && !this._isSilentFallback(locale)) {
            warn(("Value of key '" + key + "' is not a string!"));
          }
          return null
        }
      }
  
      // Check for the existence of links within the translated string
      if (ret.indexOf('@:') >= 0 || ret.indexOf('@.') >= 0) {
        ret = this._link(locale, message, ret, host, 'raw', values, visitedLinkStack);
      }
  
      return this._render(ret, interpolateMode, values, key)
    };
  
    VueI18n.prototype._link = function _link (
      locale,
      message,
      str,
      host,
      interpolateMode,
      values,
      visitedLinkStack
    ) {
        var this$1 = this;
  
      var ret = str;
  
      // Match all the links within the local
      // We are going to replace each of
      // them with its translation
      var matches = ret.match(linkKeyMatcher);
      for (var idx in matches) {
        // ie compatible: filter custom array
        // prototype method
        if (!matches.hasOwnProperty(idx)) {
          continue
        }
        var link = matches[idx];
        var linkKeyPrefixMatches = link.match(linkKeyPrefixMatcher);
        var linkPrefix = linkKeyPrefixMatches[0];
          var formatterName = linkKeyPrefixMatches[1];
  
        // Remove the leading @:, @.case: and the brackets
        var linkPlaceholder = link.replace(linkPrefix, '').replace(bracketsMatcher, '');
  
        if (visitedLinkStack.includes(linkPlaceholder)) {
          {
            warn(("Circular reference found. \"" + link + "\" is already visited in the chain of " + (visitedLinkStack.reverse().join(' <- '))));
          }
          return ret
        }
        visitedLinkStack.push(linkPlaceholder);
  
        // Translate the link
        var translated = this$1._interpolate(
          locale, message, linkPlaceholder, host,
          interpolateMode === 'raw' ? 'string' : interpolateMode,
          interpolateMode === 'raw' ? undefined : values,
          visitedLinkStack
        );
  
        if (this$1._isFallbackRoot(translated)) {
          if (!this$1._silentTranslationWarn) {
            warn(("Fall back to translate the link placeholder '" + linkPlaceholder + "' with root locale."));
          }
          /* istanbul ignore if */
          if (!this$1._root) { throw Error('unexpected error') }
          var root = this$1._root.$i18n;
          translated = root._translate(
            root._getMessages(), root.locale, root.fallbackLocale,
            linkPlaceholder, host, interpolateMode, values
          );
        }
        translated = this$1._warnDefault(
          locale, linkPlaceholder, translated, host,
          Array.isArray(values) ? values : [values]
        );
        if (formatters.hasOwnProperty(formatterName)) {
          translated = formatters[formatterName](translated);
        }
  
        visitedLinkStack.pop();
  
        // Replace the link with the translated
        ret = !translated ? ret : ret.replace(link, translated);
      }
  
      return ret
    };
  
    VueI18n.prototype._render = function _render (message, interpolateMode, values, path) {
      var ret = this._formatter.interpolate(message, values, path);
  
      // If the custom formatter refuses to work - apply the default one
      if (!ret) {
        ret = defaultFormatter.interpolate(message, values, path);
      }
  
      // if interpolateMode is **not** 'string' ('row'),
      // return the compiled data (e.g. ['foo', VNode, 'bar']) with formatter
      return interpolateMode === 'string' ? ret.join('') : ret
    };
  
    VueI18n.prototype._translate = function _translate (
      messages,
      locale,
      fallback,
      key,
      host,
      interpolateMode,
      args
    ) {
      var res =
        this._interpolate(locale, messages[locale], key, host, interpolateMode, args, [key]);
      if (!isNull(res)) { return res }
  
      res = this._interpolate(fallback, messages[fallback], key, host, interpolateMode, args, [key]);
      if (!isNull(res)) {
        if (!this._silentTranslationWarn && !this._silentFallbackWarn) {
          warn(("Fall back to translate the keypath '" + key + "' with '" + fallback + "' locale."));
        }
        return res
      } else {
        return null
      }
    };
  
    VueI18n.prototype._t = function _t (key, _locale, messages, host) {
        var ref;
  
        var values = [], len = arguments.length - 4;
        while ( len-- > 0 ) values[ len ] = arguments[ len + 4 ];
      if (!key) { return '' }
  
      var parsedArgs = parseArgs.apply(void 0, values);
      var locale = parsedArgs.locale || _locale;
  
      var ret = this._translate(
        messages, locale, this.fallbackLocale, key,
        host, 'string', parsedArgs.params
      );
      if (this._isFallbackRoot(ret)) {
        if (!this._silentTranslationWarn && !this._silentFallbackWarn) {
          warn(("Fall back to translate the keypath '" + key + "' with root locale."));
        }
        /* istanbul ignore if */
        if (!this._root) { throw Error('unexpected error') }
        return (ref = this._root).$t.apply(ref, [ key ].concat( values ))
      } else {
        return this._warnDefault(locale, key, ret, host, values)
      }
    };
  
    VueI18n.prototype.t = function t (key) {
        var ref;
  
        var values = [], len = arguments.length - 1;
        while ( len-- > 0 ) values[ len ] = arguments[ len + 1 ];
      return (ref = this)._t.apply(ref, [ key, this.locale, this._getMessages(), null ].concat( values ))
    };
  
    VueI18n.prototype._i = function _i (key, locale, messages, host, values) {
      var ret =
        this._translate(messages, locale, this.fallbackLocale, key, host, 'raw', values);
      if (this._isFallbackRoot(ret)) {
        if (!this._silentTranslationWarn) {
          warn(("Fall back to interpolate the keypath '" + key + "' with root locale."));
        }
        if (!this._root) { throw Error('unexpected error') }
        return this._root.$i18n.i(key, locale, values)
      } else {
        return this._warnDefault(locale, key, ret, host, [values])
      }
    };
  
    VueI18n.prototype.i = function i (key, locale, values) {
      /* istanbul ignore if */
      if (!key) { return '' }
  
      if (typeof locale !== 'string') {
        locale = this.locale;
      }
  
      return this._i(key, locale, this._getMessages(), null, values)
    };
  
    VueI18n.prototype._tc = function _tc (
      key,
      _locale,
      messages,
      host,
      choice
    ) {
        var ref;
  
        var values = [], len = arguments.length - 5;
        while ( len-- > 0 ) values[ len ] = arguments[ len + 5 ];
      if (!key) { return '' }
      if (choice === undefined) {
        choice = 1;
      }
  
      var predefined = { 'count': choice, 'n': choice };
      var parsedArgs = parseArgs.apply(void 0, values);
      parsedArgs.params = Object.assign(predefined, parsedArgs.params);
      values = parsedArgs.locale === null ? [parsedArgs.params] : [parsedArgs.locale, parsedArgs.params];
      return this.fetchChoice((ref = this)._t.apply(ref, [ key, _locale, messages, host ].concat( values )), choice)
    };
  
    VueI18n.prototype.fetchChoice = function fetchChoice (message, choice) {
      /* istanbul ignore if */
      if (!message && typeof message !== 'string') { return null }
      var choices = message.split('|');
  
      choice = this.getChoiceIndex(choice, choices.length);
      if (!choices[choice]) { return message }
      return choices[choice].trim()
    };
  
    /**
     * @param choice {number} a choice index given by the input to $tc: `$tc('path.to.rule', choiceIndex)`
     * @param choicesLength {number} an overall amount of available choices
     * @returns a final choice index
    */
    VueI18n.prototype.getChoiceIndex = function getChoiceIndex (choice, choicesLength) {
      // Default (old) getChoiceIndex implementation - english-compatible
      var defaultImpl = function (_choice, _choicesLength) {
        _choice = Math.abs(_choice);
  
        if (_choicesLength === 2) {
          return _choice
            ? _choice > 1
              ? 1
              : 0
            : 1
        }
  
        return _choice ? Math.min(_choice, 2) : 0
      };
  
      if (this.locale in this.pluralizationRules) {
        return this.pluralizationRules[this.locale].apply(this, [choice, choicesLength])
      } else {
        return defaultImpl(choice, choicesLength)
      }
    };
  
    VueI18n.prototype.tc = function tc (key, choice) {
        var ref;
  
        var values = [], len = arguments.length - 2;
        while ( len-- > 0 ) values[ len ] = arguments[ len + 2 ];
      return (ref = this)._tc.apply(ref, [ key, this.locale, this._getMessages(), null, choice ].concat( values ))
    };
  
    VueI18n.prototype._te = function _te (key, locale, messages) {
        var args = [], len = arguments.length - 3;
        while ( len-- > 0 ) args[ len ] = arguments[ len + 3 ];
  
      var _locale = parseArgs.apply(void 0, args).locale || locale;
      return this._exist(messages[_locale], key)
    };
  
    VueI18n.prototype.te = function te (key, locale) {
      return this._te(key, this.locale, this._getMessages(), locale)
    };
  
    VueI18n.prototype.getLocaleMessage = function getLocaleMessage (locale) {
      return looseClone(this._vm.messages[locale] || {})
    };
  
    VueI18n.prototype.setLocaleMessage = function setLocaleMessage (locale, message) {
      this._vm.$set(this._vm.messages, locale, message);
    };
  
    VueI18n.prototype.mergeLocaleMessage = function mergeLocaleMessage (locale, message) {
      this._vm.$set(this._vm.messages, locale, merge(this._vm.messages[locale] || {}, message));
    };
  
    VueI18n.prototype.getDateTimeFormat = function getDateTimeFormat (locale) {
      return looseClone(this._vm.dateTimeFormats[locale] || {})
    };
  
    VueI18n.prototype.setDateTimeFormat = function setDateTimeFormat (locale, format) {
      this._vm.$set(this._vm.dateTimeFormats, locale, format);
    };
  
    VueI18n.prototype.mergeDateTimeFormat = function mergeDateTimeFormat (locale, format) {
      this._vm.$set(this._vm.dateTimeFormats, locale, merge(this._vm.dateTimeFormats[locale] || {}, format));
    };
  
    VueI18n.prototype._localizeDateTime = function _localizeDateTime (
      value,
      locale,
      fallback,
      dateTimeFormats,
      key
    ) {
      var _locale = locale;
      var formats = dateTimeFormats[_locale];
  
      // fallback locale
      if (isNull(formats) || isNull(formats[key])) {
        if (!this._silentTranslationWarn) {
          warn(("Fall back to '" + fallback + "' datetime formats from '" + locale + " datetime formats."));
        }
        _locale = fallback;
        formats = dateTimeFormats[_locale];
      }
  
      if (isNull(formats) || isNull(formats[key])) {
        return null
      } else {
        var format = formats[key];
        var id = _locale + "__" + key;
        var formatter = this._dateTimeFormatters[id];
        if (!formatter) {
          formatter = this._dateTimeFormatters[id] = new Intl.DateTimeFormat(_locale, format);
        }
        return formatter.format(value)
      }
    };
  
    VueI18n.prototype._d = function _d (value, locale, key) {
      /* istanbul ignore if */
      if (!VueI18n.availabilities.dateTimeFormat) {
        warn('Cannot format a Date value due to not supported Intl.DateTimeFormat.');
        return ''
      }
  
      if (!key) {
        return new Intl.DateTimeFormat(locale).format(value)
      }
  
      var ret =
        this._localizeDateTime(value, locale, this.fallbackLocale, this._getDateTimeFormats(), key);
      if (this._isFallbackRoot(ret)) {
        if (!this._silentTranslationWarn) {
          warn(("Fall back to datetime localization of root: key '" + key + "' ."));
        }
        /* istanbul ignore if */
        if (!this._root) { throw Error('unexpected error') }
        return this._root.$i18n.d(value, key, locale)
      } else {
        return ret || ''
      }
    };
  
    VueI18n.prototype.d = function d (value) {
        var args = [], len = arguments.length - 1;
        while ( len-- > 0 ) args[ len ] = arguments[ len + 1 ];
  
      var locale = this.locale;
      var key = null;
  
      if (args.length === 1) {
        if (typeof args[0] === 'string') {
          key = args[0];
        } else if (isObject(args[0])) {
          if (args[0].locale) {
            locale = args[0].locale;
          }
          if (args[0].key) {
            key = args[0].key;
          }
        }
      } else if (args.length === 2) {
        if (typeof args[0] === 'string') {
          key = args[0];
        }
        if (typeof args[1] === 'string') {
          locale = args[1];
        }
      }
  
      return this._d(value, locale, key)
    };
  
    VueI18n.prototype.getNumberFormat = function getNumberFormat (locale) {
      return looseClone(this._vm.numberFormats[locale] || {})
    };
  
    VueI18n.prototype.setNumberFormat = function setNumberFormat (locale, format) {
      this._vm.$set(this._vm.numberFormats, locale, format);
    };
  
    VueI18n.prototype.mergeNumberFormat = function mergeNumberFormat (locale, format) {
      this._vm.$set(this._vm.numberFormats, locale, merge(this._vm.numberFormats[locale] || {}, format));
    };
  
    VueI18n.prototype._localizeNumber = function _localizeNumber (
      value,
      locale,
      fallback,
      numberFormats,
      key,
      options
    ) {
      var _locale = locale;
      var formats = numberFormats[_locale];
  
      // fallback locale
      if (isNull(formats) || isNull(formats[key])) {
        if (!this._silentTranslationWarn) {
          warn(("Fall back to '" + fallback + "' number formats from '" + locale + " number formats."));
        }
        _locale = fallback;
        formats = numberFormats[_locale];
      }
  
      if (isNull(formats) || isNull(formats[key])) {
        return null
      } else {
        var format = formats[key];
  
        var formatter;
        if (options) {
          // If options specified - create one time number formatter
          formatter = new Intl.NumberFormat(_locale, Object.assign({}, format, options));
        } else {
          var id = _locale + "__" + key;
          formatter = this._numberFormatters[id];
          if (!formatter) {
            formatter = this._numberFormatters[id] = new Intl.NumberFormat(_locale, format);
          }
        }
        return formatter.format(value)
      }
    };
  
    VueI18n.prototype._n = function _n (value, locale, key, options) {
      /* istanbul ignore if */
      if (!VueI18n.availabilities.numberFormat) {
        {
          warn('Cannot format a Number value due to not supported Intl.NumberFormat.');
        }
        return ''
      }
  
      if (!key) {
        var nf = !options ? new Intl.NumberFormat(locale) : new Intl.NumberFormat(locale, options);
        return nf.format(value)
      }
  
      var ret =
        this._localizeNumber(value, locale, this.fallbackLocale, this._getNumberFormats(), key, options);
      if (this._isFallbackRoot(ret)) {
        if (!this._silentTranslationWarn) {
          warn(("Fall back to number localization of root: key '" + key + "' ."));
        }
        /* istanbul ignore if */
        if (!this._root) { throw Error('unexpected error') }
        return this._root.$i18n.n(value, Object.assign({}, { key: key, locale: locale }, options))
      } else {
        return ret || ''
      }
    };
  
    VueI18n.prototype.n = function n (value) {
        var args = [], len = arguments.length - 1;
        while ( len-- > 0 ) args[ len ] = arguments[ len + 1 ];
  
      var locale = this.locale;
      var key = null;
      var options = null;
  
      if (args.length === 1) {
        if (typeof args[0] === 'string') {
          key = args[0];
        } else if (isObject(args[0])) {
          if (args[0].locale) {
            locale = args[0].locale;
          }
          if (args[0].key) {
            key = args[0].key;
          }
  
          // Filter out number format options only
          options = Object.keys(args[0]).reduce(function (acc, key) {
              var obj;
  
            if (numberFormatKeys.includes(key)) {
              return Object.assign({}, acc, ( obj = {}, obj[key] = args[0][key], obj ))
            }
            return acc
          }, null);
        }
      } else if (args.length === 2) {
        if (typeof args[0] === 'string') {
          key = args[0];
        }
        if (typeof args[1] === 'string') {
          locale = args[1];
        }
      }
  
      return this._n(value, locale, key, options)
    };
  
    Object.defineProperties( VueI18n.prototype, prototypeAccessors );
  
    var availabilities;
    // $FlowFixMe
    Object.defineProperty(VueI18n, 'availabilities', {
      get: function get () {
        if (!availabilities) {
          var intlDefined = typeof Intl !== 'undefined';
          availabilities = {
            dateTimeFormat: intlDefined && typeof Intl.DateTimeFormat !== 'undefined',
            numberFormat: intlDefined && typeof Intl.NumberFormat !== 'undefined'
          };
        }
  
        return availabilities
      }
    });
  
    VueI18n.install = install;
    VueI18n.version = '8.9.0';
  
    return VueI18n;
  
  })));